Question 1

In the following Lewis structure for phosphate, phosphorus has a formal charge of ____ and an oxidation number of ____.

Accepted Answer

A)  0; -3 
B)  0; 5 
C)  5; -3 
D)  5; 5 
E)  3; 5 
A)  0; -3 
B)  0; 5 
C)  5; -3 
D)  5; 5 
E)  3; 5

Question 2

What is the molecular shape of ClCN as predicted by the VSEPR theory? (Carbon is the central atom.)

Accepted Answer

A)  linear 
B)  bent 
C)  angular 
D)  trigonal 
E)  None of these choices are correct. 
A)  linear 
B)  bent 
C)  angular 
D)  trigonal 
E)  None of these choices are correct.

Question 3

When resonance occurs, the bond lengths in a molecule fluctuate rapidly.

Accepted Answer

A) True 
 B)False

Question 4

In neutral molecules, how many bonds are commonly formed by nitrogen? And how many by oxygen?

Accepted Answer

A)  5 and 6 
B)  4 and 2 
C)  3 and 6 
D)  4 and 6 
E)  3 and 2 
A)  5 and 6 
B)  4 and 2 
C)  3 and 6 
D)  4 and 6 
E)  3 and 2

Question 5

The best Lewis structure for sulfuric acid has zero formal charges, sulfur as the central atom, and no bonds between S and H. How many single and double bonds, respectively, are there in this Lewis structure?

Accepted Answer

A)  2 single, 4 double 
B)  4 single, 2 double 
C)  4 single, no double 
D)  6 single, no double 
E)  5 single, 1 double 
A)  2 single, 4 double 
B)  4 single, 2 double 
C)  4 single, no double 
D)  6 single, no double 
E)  5 single, 1 double

Question 6

In which one of the following molecules are all the bonds single?

Accepted Answer

A)  O3 
B)  POCl3 
C)  CO 
D)  COCl2 
E)  N2H4 
A)  O3 
B)  POCl3 
C)  CO 
D)  COCl2 
E)  N2H4

Question 7

The Lewis structure of NO2 violates the octet rule.

Accepted Answer

A) True 
 B)False

Question 8

Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90° bond angle in it. (In each case except water, the central atom is the first one in the formula.)

Accepted Answer

A)  AlCl4- 
B)  NH3 
C)  PCl5 
D)  CO2 
E)  H2O 
A)  AlCl4- 
B)  NH3 
C)  PCl5 
D)  CO2 
E)  H2O

Question 9

Select the correct Lewis structure for TeBr2.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 10

In which one of the following species is the central atom (the first atom in the formula) an exception to the octet rule?

Accepted Answer

A)  NH3 
B)  NH4+ 
C)  I2 
D)  BH4- 
E)  SF6 
A)  NH3 
B)  NH4+ 
C)  I2 
D)  BH4- 
E)  SF6

Question 11

In carbon disulfide, how many lone pairs of electrons are on each sulfur atom?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  4 
A)  0 
B)  1 
C)  2 
D)  3 
E)  4

Question 12

According to VSEPR theory, a molecule with the general formula AX4E will have a _____ molecular shape.

Accepted Answer

A)  bent 
B)  see-saw 
C)  trigonal planar 
D)  T-shaped 
E)  square planar 
A)  bent 
B)  see-saw 
C)  trigonal planar 
D)  T-shaped 
E)  square planar

Question 13

In the following Lewis structure for ClO3F, chlorine has a formal charge of ____ and an oxidation number of ____.

Accepted Answer

A)  7; 7 
B)  7; -1 
C)  1; 1 
D)  1; -1 
E)  1; 7 
A)  7; 7 
B)  7; -1 
C)  1; 1 
D)  1; -1 
E)  1; 7

Question 14

Predict the smallest actual bond angle in BrF3 using the VSEPR theory.

Accepted Answer

A)  more than 120° 
B)  exactly 120° 
C)  between 109° and 120° 
D)  between 90° and 109° 
E)  less than 90° 
A)  more than 120° 
B)  exactly 120° 
C)  between 109° and 120° 
D)  between 90° and 109° 
E)  less than 90°

Question 15

How many resonance structures are possible for NO3-?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 16

Predict the ideal bond angles in IF2- using the molecular shape given by the VSEPR theory.

Accepted Answer

A)  60° 
B)  90° 
C)  109° 
D)  120° 
E)  180° 
A)  60° 
B)  90° 
C)  109° 
D)  120° 
E)  180°

Question 17

According to VSEPR theory, a molecule with the general formula AX2 will have a ___ molecular shape.

Accepted Answer

A)  linear 
B)  bent 
C)  trigonal planar 
D)  tetrahedral 
E)  triangular 
A)  linear 
B)  bent 
C)  trigonal planar 
D)  tetrahedral 
E)  triangular

Question 18

According to VSEPR theory, a molecule with the general formula AX3E2 (where E represents a lone pair on A) will be trigonal planar.

Accepted Answer

A) True 
 B)False

Exam 10: The Shapes of Molecules

In the following Lewis structure for phosphate, phosphorus has a formal charge of ____ and an oxidation number of ____.

What is the molecular shape of ClCN as predicted by the VSEPR theory? (Carbon is the central atom.)

When resonance occurs, the bond lengths in a molecule fluctuate rapidly.

In neutral molecules, how many bonds are commonly formed by nitrogen? And how many by oxygen?

The best Lewis structure for sulfuric acid has zero formal charges, sulfur as the central atom, and no bonds between S and H. How many single and double bonds, respectively, are there in this Lewis structure?

In which one of the following molecules are all the bonds single?

The Lewis structure of NO2 violates the octet rule.

Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90° bond angle in it. (In each case except water, the central atom is the first one in the formula.)

Select the correct Lewis structure for TeBr2.

In which one of the following species is the central atom (the first atom in the formula) an exception to the octet rule?

In carbon disulfide, how many lone pairs of electrons are on each sulfur atom?

According to VSEPR theory, a molecule with the general formula AX4E will have a _____ molecular shape.

In the following Lewis structure for ClO3F, chlorine has a formal charge of ____ and an oxidation number of ____.

Predict the smallest actual bond angle in BrF3 using the VSEPR theory.

How many resonance structures are possible for NO3-?

Predict the ideal bond angles in IF2- using the molecular shape given by the VSEPR theory.

According to VSEPR theory, a molecule with the general formula AX2 will have a ___ molecular shape.

According to VSEPR theory, a molecule with the general formula AX3E2 (where E represents a lone pair on A) will be trigonal planar.

Keys to Studying Chemistry Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

Theories of Covalent Bonding

Intermolecular Forces Liquids, Solids, and Phase Changes

The Properties of Mixtures Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics Rates and Mechanisms of Chemical Reactions

Equilibrium the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

In the following Lewis structure for phosphate, phosphorus has a formal charge of and an oxidation number of .

The Lewis structure of NO₂ violates the octet rule.

Select the correct Lewis structure for TeBr₂.

According to VSEPR theory, a molecule with the general formula AX₄E will have a _____ molecular shape.

In the following Lewis structure for ClO₃F, chlorine has a formal charge of and an oxidation number of .

Predict the smallest actual bond angle in BrF₃ using the VSEPR theory.

How many resonance structures are possible for NO₃^-?

Predict the ideal bond angles in IF₂^- using the molecular shape given by the VSEPR theory.

According to VSEPR theory, a molecule with the general formula AX₂ will have a ___ molecular shape.

According to VSEPR theory, a molecule with the general formula AX₃E₂ (where E represents a lone pair on A) will be trigonal planar.